Needle-thread pull-off means



Oct. 6,1925. 8"

G. L. SUMMERS NEEDLE THREAD PULL OFF MEANS Filed July 9.,1920

Patented Oct. 6, 1925 UNITED STATES Parent orrics GILBERT LAWRENCE SU MMERS, O35 NOTTINGHALI, ENGLAND, ASSIGNOR TO WILLGOX 85 GIBBS SEWING MACHINE 30., OF NEW YORK, N. Y., A CORPORATION F NEW YORK.

NEEDIZJE'THREAD PULL-OFF MEANS.

Application filed. July 29, 1920. Serial No. 399,709.

To all whom it may concern:

Be it known that I, GILBERT LAWRENCE SUMMERS, subject of the King of Great Britain, and resident of Nottingham, England,

have invented new and useful Improvements in Needle-Thread Pull-Off Means, which invention is fully set forth in the following specification.

This invention relates to slack thread pulloff means for sewing machines. 'Although designed especially for use with the machine known commercially as the "d illcox h Gibbs Sewing Machine Companys Flatlock machine shown, for example, in the patents to A. A. Merritt, No.- 1,04l1,652, dated October th, 1912, sewing machine? and GarretB. Osterhout, No. 1,184A82, dated rxpril 6th, 191.5,.rotary take-up the pull-off means of this invention are not restricted to use with any particular type or make of sewing machine. I r

In forming a so-called interior or closedend seam, such as those on the sides of ladies underwear begun at a point relatively distant from the edge of the material it is important that the formation of perfect stitches should begin with the very first stroke of the needles, because missed or imperfect stitches even at the start of such a seam result in marred appearance and defective work. In forming such interior seams with the aforesaid Flatlock machine. some operatives have experienced missed or malformed stitches at the beginning of the Ti seam. The probable cause is that in starting or preparing to start the scam the some what lengthy thread-ends ordinarily left at the finish of a preceding operation are severed by the blades of the trimmer mechanism at the first stitch-forming operation of the parts. thus leaving only short lengths of the needle-threads beyond theeyes ofrthe needles inadequate to enable the pressure of the presser-foot to grip and anchor said thread-ends against the back-pull" imposed thereon as the needles descend to pull more needle-thread through the tensions and form needle-thread loops through the work to be entered by the loopers. Such failure to hold the needle-thread ends, and the consequent.

fa l re to fo m n ed e-t e d loop for the looper-threads, result in one or more missed 1 The principal ob ect of this invention is the provision of automatically operating pull-off means which will overcome the aforesaid ditiiculties by providing slack in the needle-threads between the tension means and the eyes of the needles "suflicient to accommodate the clown-stroke of the needles in beginning a seam without imposing; backpull upon said threads sufficient to draw the relatively short ends thereof down through the work. In operating a sewing machine, such as the aforesaid Flatlock "the operator, in making ready to begin an operation of the machine at the closed end of a seam, unlocks the needle-threads from the lcoper thrcads.- This is accomplished by rotating the machine, as by hand manipulation, in its normal direction until the needles are at their lowest point through the work-plate and then rotating the machine in the reverse direction one-half a revolution or until the needles are at their highest point above the work-plate. Another object of this invention is to take advantage of such unlocking manipulation or reverse rotation to automatically actuate thread pull-off means to provide the aforesaid desired slack in the needle threads available to the needles in beginning a seam at its closed end. Another object is to provide thread pull-off means which will be inoperative upon the thread while the machine is rotating in normal direction but which upon the aforesaid re verse rotation of the machine will promptly and automatically pull sutlicient thread from the source of supply and past the tension means to supply the desired slack in advance of the needles when the machine is thereafter operated to begin a seam; Another obiect till more fully understood from the following detailed explanation with reference to the accompanying drawing illustrating what is now believed to be the preferred embodiment of the invention as applied to a machine of the character of the aforesaid Flatlock machine.

In said drawing Figs. 1 and 2 are vertical sectional views through a portion of a sewing machine having pull-off means of this invention applied to a rotary take-up of the machine, said figures showing the position of parts when the needles are down and up respectively;

Fig. 3 is a detail perspective of the pulloff means; i

Fig. 4 is a detail elevation showing one position of the pull-off means with respect to the needle threads in the forward rotation of said means;

Fig. 5 is a view similar to Fig. 4 showing the action of the pull-off means in beginningv to grip the needle threads upon reverse rota tion of said means; 7

Fig. 6 is a side elevation corresponding to Fig. 5; and

Fig. 7 is a front elevation of the rotary take-up with the pull-off means applied thereto.

10 is a part of the bridge portion of the frame work of a sewing machine of the type illustrated in the aforesaid Merritt patent; 11 is a bracket mounted on said bridge portion and supporting a thread guide 12 and tension disks 13 for a cross-thread A thread guide 15, tension plates 16 for four needle threads 17, and. five thread guiding hooks 18, for the four needle threads and the cross thread respectively, are also mounted on the bracket 11. At 19 there is shown a second set of thread guiding hooks mounted on the bridge portion 10, one for each of the threads respectively, from which hooks the four needle threads 17 pass to thread uiding openings 20 on the head of the ma chine (only a portion of which head is shown in Figs. 1 and 2), thence through thread uiding openings 21 at the lower end of the needle bar to the four needles 22 respectively. The dotted line 23 in each of Figs. 1 and 2 indicates the approximate position of the upper surface of the throat plate of the machine, these two views. as before stated, showing the relative positions of the parts at different stages of the movement thereo in the stitch forming cvcle. 25 is a horizontal take-up shaft suitably journaled in the frame-work of the machine. It is shown in this particular instance as carrying a double take-up fixed upon the shaft by a set-screw 26. One cam portion 32 of said take-up, between flanges, disks or plates 28 and 29, is adapted to act upon the cross thread 14, and another cam portion 34 of said take-up, between the flanges or disks 29 and 31, is adapted to act upon the four needle threads 17. The threads pass over the take-up bet-ween the thread guiding hooks 18 and 19 before mentioned.

The cam portion 34 has a flattened surface 36. is an adjustable extension of am 34. Part 35 has a nose 39 at one end and a foot 39 at its other end contacting the flat face 36. it screw 37 countersunk in part 35 secures it to part 34. An adjusting screw 38 countersunk in a screw-threaded opening in the adjustable cam part 35 hears at its inner srojecting end against the end of the surface 36 of part 34. When it is desired to adjust the take-up to give greater action upon the needle threads, the set screw 37 is first loosened and the adjusting screw 38 then turned to move the adjustable cam part 35 outwardly to the desired extent and the set screw 37 then again tightened. To lessen the action of the take-up upon the needle threads, this manipulation of the parts is reversed. The parts thus far referred to in the detailed description are similar to corresponding parts illustrated and described in the aforesaid Osterhout patent.

In the embodiment of the pull-off means of the present invention shown in the drawing, said means comprise four slightly curved parallel fingers, hooks or prongs 40, 41, 42 and 4?, preferably formed inte ral with a plate 44 which fits in a recess of nose 39 of take-up 35. Two screws 46, 46, secure the plate in said recess. The fingers are arranged in pairs; thus fingers 40 and 41 constitute one pair and 42 and 43 another the fingers of each pair being separated by a narrow slot flaring at its outer end where the pointed ends of the fingers diverge. In the position of the needle threads and fingers shown in, lii 4 (and approximately the same giositions of ly and 3) the right-hand needle thread lies at the right of finger 43 with the point of said finger cu'ving to the right over said thread. the third thread from the right being similarly positioned with relation to finger 41: the second thread from the right lies at the left of. finger 42 with the point of said finger curving to the left over said thread, the thread at the extr me left being similarly positioned with relation to finger 40; and the four threads rest in guide notches respectively of plate 44. lVith the sewing machine running in its usual or normal direction. that is forward, and the take-up and pull-off ngers rotating in the direction of the full-line arrows of Figs. 1 4, said take-up makes one rotation for each stitchforming stroke of t is need es and in thus tightening each stitch also pulls thread for the next stitch of each needle from the source of thread supply and past the tension plates, said fingers in such forward rotation and then rotating the machine one-half a revolution in reverse direction until the drawn to the position shown in Fig. 2 when the needles have reached their uppermost position. A surplus of the needle threads is thus drawn through the tension plates and retained in the slots'and around the fingers, the length of each thread so drawn past the tension plates being considerably in excess of the length of said thread drawn past said tension plates by a'corresponding forward rotation of the pull-ofli' means. Fig. 5 shows the action of the fingers as they begin to crowd the threads into the slots; in Fig. 2 the threads areat'the inner ends of the slots. In this manner surplus of-needle threads is supplied and controlled until after the goods have been correctly placed and the presserfootlowered. When the machin'e is started the surplus of needle threads is immediately liberated from the pull-off fingers in sufficient quantity to ensure perfect stitches from the commencement of the seam."

What is claimed as new is 1. In a sewing machine, the combination with stitch-forming mechanism including one or more needles, of needle-thread pullolf means actuated by reverse rotation of the machine only to pull off needle-thread from its source of supply forthe needle or needles in subsequent operation of the machine.

2. In a sewing machine, the combination with stitch-forming mechanism andthreadtensioning means, of thread pull-ofii' means actuated by reverse rotation of the machine only to pull thread past the tensioning means and available to the stitch-forming mechanism in subsequent operation'of the machine. i

'3. In a sewing machine, the combination with stitch-forming mechanism, including one'or more needles, and thread-tensioning means, of thread pull-oil means actuated'by r er e ota on of the mach e only t p l needle-thread past the tensioning means and available to the needle or needles in subsequent operation of the machine.

4. In a sewing machine, the combination with stitch-forming mechanism including one or vmore needles, of rotatable needle thread pull-off means rotated by reverse rotationof the machine and acting only in such reverse rotation to pull off needlethread from" its source of supply for the needle or needles in subsequent operation of the machine.

5. In a sewing machine, the combination with stitch-forming mechanism and thread tensioning means, of rotary thread pull-oil means adapted to operateonly upon reverse rotation of the machine, and driving connections actuating said pull-off means upon reverse rotation of the machine to pull thread past the tensioning means and available to the stitch-forming mechanism in subsequent operation thereof.

6. Ina sewing machine, the combination with stitch-forming mechanism, including oneor more needles, and thread-tensionin means, of rotary needle-thread pull-0E means adapted to operate only upon reverse rotation of the machine, and driving'con nections actuating said pull-off means upon reverse rotation of the machine to pull needle-thread past the tensioning-means and available to the needles in subsequent operation thereof.

7 In a sewing machine, the combination with stitch-forming mechanism and threadtensioning means, of rotatable thread pulloff means inactive upon the thread in the normal running of the machine, and means rotating said pull-off means to pull thread. past the tension means upon reverse rotation of the machine and available to the stitchforming mechanism.

8. In alsewing machine, rotary pull-off means adapted when rotated in one direction by reverse rotation of the machine to engage and pull the thread from the source of supply and when rotated in the other direction by forward rotation of the machine to re-- lease said thread and thereafter remain inactive upon the thread un'til again rotated in the direction first named, and driving connections for rotating said pull-off means.

9. In a sewing machine, the combination with stitch-forming mechanism, including one or more needles, and thread-tensioning means, 'of rotary ,heedle-thread pull-off means adapted when-rotated in one direction by reverse rotation of the machine to engage and pull theneedle thread or threads from the source of supply and past the threadtensioning means and when rotated in the other direction by forward rotation of the machine to release said thread and thereafter emai inactive u on, the h ea un il again rotated in the direction first named, and driving connections for rotating said pull-off means.

10. In a sewing machine, the combination 'ith stitch-forming mechanism including one or more needles, thread-tensioning means, and a rotary needle thread take-up, of needle thread pull-off means comprising fingers on said rotary take-up adapted to engage and pull the needle-thread or threads from the source of supply and past the tensioning-means when the take-up rotates in one direction and to release and re main inactive upon said thread when the take-up rotates in the other direction.

11. In a sewing machine, the combination with stitch-forming mechanism, of rotatable thread pull-off means inactive upon the thread in the normal direction of running of the machine but rotated upon reverse rotation of the machine to pull thread from its source of supply available to the stitchforming mechanism in subsequent stitchforming operation thereof.

12. In a sewing machine, the combination with stitch-forming mechanism, of thread pull-off means inactive in rotation of the machine in normal direction but operating upon rotation of the machine in reverse direction to pull thread from the source of thread supply and available to the stitchforming mechanism in subsequent operation thereof.

13. In a sewing machine, the combination with stitch-forming mechanism including one or more needles, of rotatable needle thread pull-off means inactive in rotation of the machine in normal direction but operating automatically upon rotation of the machine in reverse direction to pull needle thread from the source of supply thereof and available to the needle or needles in subsequent stitch-forming operation of the 'stitchforming mechanism.

14. In a sewing machine, the combination of stitch-forming mechanism, of means operating automatically upon rotation of the machine in one direction to pull stitchforming thread from its source of supply, and means operating automatically only upon rotation of the machine in the other direction to pull stitch-forming thread from its source of supply.

1.5. In a sewing machine, the combination of stitch-forming mechanism including one or more needles, of means operating automatically upon rotation of the machine in normal direction to pull needle thread from its source of supply, and means operating automatically only upon reverse rotation of the machine to pull needle thread from its source of supply.

16. In a sewing machine, the combination of stitch-forming mechanism, of a rotary take-up for stitch-forming thread, means rotating with the take-up to pull stitch-forming thread from its source of supply in one direction only of rotation of the take-up.

17. In a sewing machine, the combination of stitch-forming mechanism, of a rotary take-up for stitch-forming thread, means ro tating with the take-up to pull stitclrforming thread from its source of supply in the reverse direction of rotation but not in the normal direction of rotation of the takean 18. In a sewing machine, the combination with stitch-forming mechanism, of a takeup for stitch-forming thread, and means movable with said take-up to pull stitchforming thread from its source of supply in one direction only of operation of the machine.

19. In a sewing machine, the combination with stitcl1forming mechanism, of thread pull-off means actuated by both forward and reverse rotation of the machine, said means being inactive upon the stitch-forming thread when the machine is rotated in forward direction but acting when the machine is rotated in reverse direction to pull said thread from its source of supply and available to the stitchforming mechanism in subsequent stitch-forming operation thereof.

20. In a sewing machine, the combination with stitch-forming mechanism, of thread pull-off means acting in the forward rotation of the machine to pull thread from the source of supply for the formation of stitches, and thread pull-off means acting in the reverse rotation of the machine topull from the source of supply a greater length of thread than is pulled therefrom by the first named pull-off means by a corresponding forward rotation of the machine.

21. In a sewing machine, the combination with stitch-forming mechanism. of thread pull-oif means operable to pull thread from its source of supply both upon forward and reverse rotation of the machine, said pull-oft means acting to pull a greater length of thread from the source of supply on reverse rotation of the machine than on forward rotation thereof.

22. In a sewing machine. the combination with stitch-forming mechanism. of rotary thread pulloff means operable in both directions of rotation thereof to pull thread from the source of thread supply, said pulloff means acting to pull greater length of thread from the source of supply in one direction of rotation of said means than in the other direction of rotation thereof.

23. In a sewing machine, the combina tion with stitch-forming mechanism and thread-tensioning means, of rotary thread pull-off means, and driving connections actuating said means to pull from thesource of supply past the tensioning means thread in excess of the amount' of thread drawn from said source of supply and past the tensioning means for each stitch in the normal running of the machine.

24. In a sewing machine, the combination with stitch-forming mechanism including one or more needles and thread-tensioning means, of rotary needle-thread pull-0E means, acting to pull needle-thread past the tensioning means upon both the forward 10 and reverse rotations of the machine and operating in said reverse rotation to pull greater length of such thread pastthe tensions than in forward rotation.

In testimony whereof I have signed this 15 specification.

i GILBERT LAWRENCE SUMMERS. 

